[FEATURE]: Add filter for active integrations and ability to disconnect / revoke credentials. #57680

Feature hasn't been suggested before.

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Describe the enhancement you want to request

Summary

The current "Connect an integration" menu displays all available providers, marking connected ones with a checkmark. However, as the list of services grows, it becomes difficult to quickly manage already active integrations.

I would like to propose adding:

1. A way to filter the list by active/connected integrations.
2. The ability to disconnect an integration directly from this menu (or clear/unset the associated credentials).

Problem / Motivation

• Finding active services: With dozens of services listed under categories like MCP, Popular, and Services, users have to scroll through the full list to check what is currently connected.
• Disconnecting / Revoking: Currently, it is not immediately clear how to disconnect a provider or revoke credentials once added. If an integration was enabled via an API key stored by OpenCode, there should be an option to remove it. If the provider is active due to an environment variable, the UI should guide the user on which environment variable needs to be removed.

Proposed Solution / UX Ideas

• Filter:
  • Add a dedicated category or filter option at the top (e.g., Connected / Active section, or a quick filter toggle/shortcut like is:connected).
• Management / Disconnect action:
  • Selecting an already connected provider could open a submenu or modal with an option to:
    • Disconnect / Remove API key: Delete the stored key/token from config.
    • Env var hint: If the provider is activated via an environment variable (e.g., ANTHROPIC_API_KEY, OPENAI_API_KEY), display a message explaining how to unset it: "Connected via environment variable ENV_VAR_NAME. Unset or remove this variable from your environment to disconnect."